title: [Studies on contrast medium dosage in perfusion-weighted MR imaging].
abstract: OBJECTIVE
  In this study we investigated, whether increasing the dosage of a paramagnetic contrast agent results in a stronger signal decrease in T2*-weighted perfusion sequences and therefore more meaningful parameter maps.
  
  
  METHODS
  In a prospective study bolus injection of gadolinium-DTPA was performed at dosages of 0.1, 0.2, and 0.3 mmol/kg body weight (BW) in 10 patients each. Before, during and after bolus injection 40 T2*-weighted images of a reference brain slice were acquired within 65.6 seconds on a 1.0 T clinical scanner and perfusion parameters were calculated.
  
  
  RESULTS
  Due to the limited signal decrease during bolus passage and the resulting low signal-difference-to-noise ratio (delta S/N) no reliable differentiation of gray and white matter was possible at a contrast agent dosage of 0.1 mmol/kg BW. Only at higher dosages, both, signal decrease and delta S/N were strong enough to allow differentiation of gray and white matter and to yield reliable parameter maps.
  
  
  CONCLUSIONS
  For meaningful MR perfusion imaging at 1.0 T and with the given sequence a contrast agent dosage of at least 0.2 mmol/kg BW is necessary, if a 0.5-molar contrast agent is used.
authors.affiliation: Abteilung Neuroradiologie, Universität Heidelberg.
authors.forename: G
authors.initials: G
authors.lastname: Erb
authors.forename: T
authors.initials: T
authors.lastname: Benner
authors.forename: S
authors.initials: S
authors.lastname: Heiland
authors.forename: W
authors.initials: W
authors.lastname: Reith
authors.forename: K
authors.initials: K
authors.lastname: Sartor
authors.forename: M
authors.initials: M
authors.lastname: Forsting
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000033:anatomy & histology*; D002560:Cerebrovascular Circulation; D003287:Contrast Media / Q000008:administration & dosage*; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006801:Humans; D007275:Injections, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
vernacular_title: Untersuchungen zur Kontrastmitteldosierung bei der perfusionsgewichteten MRT.